Improvement in fog-alarms



c. & a. m. STEVENS.

Fog Alarms.

No. 141,396. Fatentedjuly 29,1873.

lllllll-fllllllllllllfllll' O Wrrmassas D luveu'roas AM, PHOTO 'L ITHOGHAPlI/C no. N. xmss'amvs's macsss) NITED STATES COLLINS STEVENS AND GEORGE M. STEVENS, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN FOG-ALARMS.

Specification forming part of Letters Patent No. 141,396, dated July 29, 1873; application filed March 27, 12572. 1

To all whom it may concern Be it known that we, COLLINS STEVENS and GEORGE M. STEvENs, all of Boston, in the county of Suffolk and State of Massachusetts, have invented a certain new and useful Fog- Signal, of which the following is a specifioa tion:

The nature of our invention consists in combining with the striking device of a fogsignal an improved let-off and timing device. By means of the let-off a series of blows may be struck at regular intervals. The intervals, being timed by a pendulum-escapement, are precise. By means of the count-wheel the continuous series of blows may be divided into a series having irregular intervals. Thus the instrument may strike one blow then, after a short interval, strike two blows in succession, and after another interval, strike three blows, thus indicating the number one hundred and twenty-three.

If the count-wheel is omitted altogether, then the intervals between the blows may be of any desired length, and all equal, or each interval in a series may be different.

A more definite understanding may be had of this device by inspection of the following description and accompanying drawings.

Figure 1 represents an elevation of our machine, part of the frame being cut away to show more clearly the operation of the parts.

Fig. 2 is an elevation of a part of the detail of our invention, showing the let-off more particularl y.

The notched wheel A, Fig. 1, is to be driven by a strong spring or heavy weight. A is a rockershaft, having arms A and B. The rocker-shaft A has attached to it a cross-head, as shown in Fig. 1, at the ends of which the pawls A and A are attached. These two pawls are so guided as to serve as a kind of an escapement for the wheel A.- The hammer A, acting through the bent arm A link A and rockerarm A, serves, in connection with the spring A, as a balance for the escapement, the pressure applied to the wheel A being sufficient to keep the hammer A in mot-ionthat is, to cause it to strike, this device being known as the crane-striker. This striking would continue until the machine run down it'it were not for the stop device, which we will proceed to describe. B is a disk attached to the shaft of the wheel A, and revolving with the wheel. This disk B has its periphery cut into a series of notches, all the notches being equal in width at the periphery, but one set beingmuch deeper than the other. This disk B is attached to its shaft by a friction connection, so that when the end of the lever B is in contact with any of the notches, large or small, it may hold the disk from revolving and allow the general works to go on. By means of the short notches in the disk B it is held by the lever B when without these it would contin no to turn with the main sha-ft,-and then the intervals and number of strokes of the hammer would be interfered with; in other words, the friction of the short notches is to retard the motion of the disk, so that the time of the hammer strokes shall be properly regulated. The end of the lever B is bent at right angles at b, Fig. 2, the bent part resting in somewhat inclined, if it were not for the fact' that the bent lever B acting upon a pin near B in the lever B looks it down. D is a weight attached to an arm of the rocker-shaft D A second arm of the rocker-shaft D has attached to its extremity a latch, D This latch D rests against a pin, D affixed to the frame of the machine, the whole so arranged that so long as the latch D rests against the pin D the weight D is suspended, as shown in Fig. 2, but as the disk I) revolves one of the pins in its face will come in contact with the latch D and push it 01f from the pin D This will allow the weight D .to drop, which, in its turn, will throw up the cam D" attached to the rocker-shaft D and thus throw the end of the bent lever B away from the pin, near B and lever B. This will allow the lever B to be pushed up, which will release the arm B of the rocker-shaft A and also release the disk B This will set the striking apparaius in motion. The striking motion will continue solon g as the lever B is not allowed to drop; in other ATENT Fr -Ion.

words, until the disk B has revolved sufficiently far to present to the bent portion 1) of the lever B a deep notch. When this deep notch is presented the lever B drops, so that the shoulder B catches. the arm B and the bent lever B catches the pin near 13, as shown in Fig. 2. Here the striking apparatus re; mains stationary until the disk D with its pin, has had time to revolve sufficiently to throw off the latch D when the motion above described will be repeated. The disk D is made fast to the escapement-wheel' H, Fig. 1, and receives its motion from the spur-wheel E The spur-wheel E is made to revolve by the weight E acting through the lever E and the ratchet-wheel E. E is a lever, also attached to the ratchet-wheel E and is so arranged, in connection with a pin at B in the arm B that the forward motion of the arm B which takes place when the hammer makes its backward motion, will cause the ratchet-wheel E to revolve and lift the weight E Then, upon retreat of the arm B the weight E acting through the ratchet-wheel E and pawl, will give motion to the escapement device E H,

and consequently to the disk D the action of which has already been described. The rockershaft D carrying the lever D latch D and cam D", is thrown back into position by the a pin B, which, as the arm B moves, contacts with the arm B extending from the rockershaft D and throws it around, thus raising the weight D and causing the latch D to catch upon the fixed pin D This part of the device will remain in this position until one of the pins of the disk D throws down the latch D as has been described.

Our machine will operate follows: For

some purposes the count-wheel B maybe left oft, in which case the pins in the disk D govern the striking. This disk in our present ma chine revolves once per minute, and as it has four pins it will throw off the latch D at intervals ot' one-fourth of a minute, and that would be the striking time if the count-disk B were left off-that is, if at each motion of the hammer the lever B were free to fall so as to catch the arm B As the disk D revolves with a constant velocity it is evident that the timing of the striking could be regulated by the pins in this disk; thus, if five pins were placed in it at equal distances the hammer would strike five times per minute; if six pins, six times, 850.; butif these pins should be placed at varying distances from each other, then the blows of the hammer would take place at varyin g intervals, so that by arrangement of pins on the disk D quite a variety of intervals may be obtained. By the combination of the countwheel B with the other parts a great variety of intervals and combinations may be effected.

We claim as our invention- 1. The combination of the time-disk D with its pins, the latch D rocker-shaft D weight D cam D and bent lever B operating, in connection with the lever B and arm B as a timing and stopping device for the striker.

2. The combination of the subject-matter of the first claim with the count-wheel B operating substantially as described, and for the purpose set forth.

COLLINS STEVENS. GEORGE M. STEVENS. Witnesses:

FRANK G. PARKER, WILLIAM EnsoN. 

